Systematics of fully heavy tetraquarks

In this work, we systematically study the mass spectrum of the fully heavy tetraquark in an extended chromomagnetic model, which includes both color and chromomagnetic interactions. Numerical results indicate that the energy level is mainly determined by the color interaction, which favors the color-sextet vertical bar(QQ)(6)(c)((Q) over bar(Q) over bar)((6) over barc)> configuration over the color-triplet vertical bar(QQ)((3))over bar (c)((Q) over bar(Q) over bar)(3c)> one. The chromomagnetic interaction mixes the two color configurations and gives small splitting. The ground state is always dominated by the color-sextet configuration. We find no stable state below the lowest heavy quarkonium pair thresholds. Most states may be wide since they have at least one S-wave decay channel into two S-wave mesons. One possible narrow state is the 1+ bb (b) over bar(c ) over bar state with a mass 15719.1 MeV. It is just above the eta(b)(B) over bar (c) threshold. But this channel is forbidden because of the conservation of the angular momentum and parity.

Automated summary

The study indicates that the energy level of the fully heavy tetraquark is mainly determined by color interaction favoring the color-sextet configuration. The chromomagnetic interaction mixes the color configurations and gives small splitting. Most states may be wide with at least one S-wave decay channel, while one possible narrow state is forbidden due to conservation laws.